When Dalinar temporarily created Honor's Perpendicularity in part V, it seemed that he gathered all of the Honor-power that had become the gloryspren. I can't believe that the gloryspren represent the total of all the investiture released when Honor was splintered. After all, Cultivation's Perpendularity is stable, and it apparently requires only a portion of Cultivation's power to exist.
Would a full revival of Honor require the reintegration of more kinds of spren? Perhaps even some sapiant varieties?
It now seems inevitable that Honor will be re-constituted as part of the final fight against Odium. Will this event require the brave sacrifice of many spren? Logically, honorspren like Syl would be at the top of this list.
Given Kaladin's propensity for self-sacrifice, I can easily see Kaladin and Syl becoming martyrs in order to recreate Honor and finally defeat Odium.